Pressure feed carburetor



Feb. 16, 1937. J. HEWITSON PRESSURE FEED CARBURETOR Filed March 14, 1935 I I n I 3 c/wbo'b 1161111 55011.

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0 I 7 p. 2 ad W 2 v I 0 W L w @1 2 5 a. /l m Patented F eb. 16, 1937 UNITED STATES PATENT OFFICE PRESSURE FEED GARBURETOR Joseph Hewitson, Kalispell, Mont. Application March 14, 1935, Serial No. 11,116

5 Claims.

An object of this invention is the provision of a carburetor for internal combustion engines which will give the optimum proportions of fuel and air to the engine for carbureting the same in accordance with the varying temperatures and speeds of the engine.

Another object of the invention is that it embodies in itself thermostatic means that automatically actuate parts for producing a lean or a rich mixture of fuel for the engine. to accord with weather conditions and engine speeds.

A further object is to provide a carburetor which is of a cheap and eflicient structure and which is thermostatically controlled.

To the attainment of the above, and other objects which will later appear, the invention consists of the improvement now to be described and definitely claimed.

In the drawing, which formspart of this. specification:

Figure 1 is a sectional view through acarburetor in accordance. with thisinvention,

Figure 2 is a sectional view on the line 2-2 of Figure 1, and

Figure 3' is a detail enlarged sectional view on the line 3-3 of Figure 2.

The jacket I of the improvement is of steel or like 'metal, and is of a thickness to prevent expansion or contraction by heat or cold. The jacket is of globular shape and has a closed top and an openv bottom. In and at the top of the jacket there is an annular heat receiving chamber 2 that has a: pipe connection withthe engine exhaust, designated 2'. The inner wall of the chamber has ports 3.

Passing centrally through the closed top of the jacket I there is the tubular neck 4 of the car'- buretor body 5. The substantially'globular body 5 is located in the jacket I in close proximity to the inner wall thereof. The body 5 is thin pewter or other metal which is highly susceptible to expansion and contraction.

Formed on the neck 4 there is a closed receptacle 6 into which gasoline is pumped through a pipe Why a pump (not shown) which is operated by the engine (also not shown). Leading from the gasoline receptacle into the neck 4 there is a tube 1 that has an offset end secured in the center of the outer of two spaced plates 8 and 8 in the neck 4. This end of the tube 1 is provided with a seat for a needle valve 9 whose stem is secured to the closed top of the outer sleeve Ill of the nozzle of the improvement. The sleeve Ill has a closed top and below said top the sleeve is p ovided with a p ced se es of ann l r slits aifording gasoline outlet ports Ill. The sleeve I0 is guided for movement on a standpipe ll fixed on the plate 8'.

For a distance from its open end the sleeve ID has an offset portion or skirt I2 that isprovided 5 with slitted ports l2. Guided for movement between the skirt l2 and the standpipe ll there is the inner and short sleeve I3. The short sleeve has slits afiording ports I3 and the pipe II has slitted ports I! that normally register with the 10 ports l3, when the engine is cold and is not. in operation. i y

In the mouth of the neck. 4 there'is the throttle valve [4.

The end of the thermostatic body 5, that ex'- 15 tends through the open end of the jacket I is formed with a tubular extension l5. Thepart l5 has, on its inner end a-seat for an air inlet disk valve [6. The stem I1 of'thesvalve-l fi is hollow and is guided through a boss 'liflcen'trally formed on a spider I9 in the part I5. The stem I"! is threaded and has screwed thereon-athumb nut 20 that contacts with'and adjusts the tension of a light helical spring; 2| arranged on the stem between the nut and the boss 18; This spring regulates the opening of the valve It. The thumb nut 20 may be heldiin'spring adjusted position by a cap nut 22 which is screwed on-the stem IT. This cap nut, however, may be also screwed on a rod 23 that has a yoke 24 whose arms are piv- 30 otally connected to the sleeve Ill and may thus provide a gasoline regulating element which works in cooperation with the. air intake valve [6.

A pair of rods 25 are pivoted to and extend angularly, in opposite directions, from the short inner sleeve [3. These rods pass through bosses 26 on the outer opposite faces of the carburetor. Nuts 2'! are screwed on the threaded ends of the rods and engage with the bossesand whereby the short sleeve I3 may be adjusted longitudinally between the skirt I2 of the outer sleeve l0 and the pipe II. p v 1 The stationary standpipe II is filledwith gasoline under pressure by the fuel pump. When the engine is cold and not in motion the elements 45 of nozzle are arranged as shown in the drawing. The ports ii! are covered by the pipe H and, the ports II' and I3 are in registering alinement. The ports l2 in the skirt l2 of the sleeve Ill are arranged below the said registering ports 50 II and I3 and the sleeve l0 rests on the plate 8. The engine is turned over by the starter and opens the throttle l4 and the automatic air valve I 6. This builds up a low vacuum in the carburetor and moves the sleeve l0 and skirt 1! to 55 cause its ports l2 to register with the ports l3 and H so that the engine draws in a rich fuel because of the limited amount of air available.

7 When the engine fires the air valve will further nozzle sleeve to bring its seriesoi ports ii! to open by the suction created by the engine and the rod 23 will further raise the sleeve in in a manner to be described to uncover its series of ports H! to deliver into the air column in the carburetor body, and to cause to mix with such air, quantities of gasoline, that mix with the air so that the mixture in desired grades of richness is delivered to the engine to suit its running speeds or loads. As the engine becomes heated the exhaust gases therefrom flow into the chamber 2 and through its ports 3 onto the body 5, causing said body toexpand. The expansion of the body causes the movement of the rod 23 to move the uncovered positions, as above described. When the body expands the holding rods 25 cause the inner sleeve [3 to move and bring its ports it out of register with the ports H. The needle valve 9 functions only to close the gasoline pipe 1 when the motor is not in operation.

Myimprovement is automatic in action and dispenses with a great number of parts necessary in the construction of ordinary carburetors.

My improvement will function when arranged in any position and produces a perfect vaporization of gasolineand air when mixed in the air colunm.

Further detailed description is not believed necessary, but it is to be understood that I hold myself entitled to make suchchanges from the construction illustrated and described as fall within the scope of what I claim.

I claim: 1 I

1. A carburetor for internal combustion engines, comprising a thermostatic body having an air inlet valve, and a throttle valve, a gasoline nozzle comprising inner and outer movable members each provided with ports, and the ports gfor the outer member being arranged. in spaced series, a fixed guide pipe for the members normally closing the outer seriesof ports in the outer nozzle member and having ports normally in register with those of the inner member, means for directing gasolineunder pressure into the.

nozzle means on the closed top of the outer nozzle member. for regulating the flow of gaso- 7 line into the nozzle, means actuated by the cranking of the engine creating a suction to open the throttle and air valve, means operated by the airrvalve for moving the outer nozzle member to bring its ports to register with those in the inner member and guide pipe'and to'direct gaso line through such ports to mix with the air in the body, means actuated by the expansion of the body for successively uncovering the outer ports in the outer nozzle, member, and means actuated by such expansion for moving the inner nozzle member. I

2. A carburetor for internal combustion engines comprising an expansible body having a throttle valve at its outlet end and an air inlet valve in its other end, a gasoline nozzle in the body, comprising inner and outer movable members and a fixed guide for said members, each of said members having ports and those .of the outer member being in spaced series and initially closed by the guide member, a tube for conducting gasoline under pressure into the nozzle, a

needle valve on the outer sleeveinitially closing the tube, a rod support forthe. outer sleeve connected with the air valve, and rod supports for the inner sleeve carried by. the body, and means to heat the body to expand said body.

jbeis and a fixed guide for said members, each of said members having ports and those of the outer member being in spaced series and initially closed by the guide member, a tubefor conductneedle valve on the outer sleeve initially closing the tube, a rod support'for the outer sleeve connected with the air valve, and rod supports for the inner sleeve carried by the body, and means adjustable to all'of said rods for regulating the length'of the rods and the position of the nozzle sleeves on such rods.

4. A carburetor for internal combustion engines comprising an expansible body having a ing gasoline under pressure into the nozzle, a

throttle valve at its outlet end and an air inlet valve in its other end, a gasoline nozzle in the body, comprising inner and outer movable members and a fixed guide for said members, each of said members having ports and those of the outer member being in spaced'series and initially a closed by the guide member, a tube for conduct-, ing gasoline under pressure into the nozzle, a needle valve on the outer sleeve initially closing the tube, a rod support for the outer sleeve connected with the air. valve, and rod supports for .the inner sleeve carried by the 'body,-.a non-ex pansible jacket around the body,.fa chamber therein to receive a heating 'medium, and said chamber having ports to direct the heated medium against this body to expand the body.

5. A carburetor for internal .combustio'n'enw gines'comprlsing an expansible body having a throttle valve at its outlet end and an air inlet valve in its other end, a gasoline nozzle in the body, comprising inner and outer movable' members and a fixed guide for said members, each of said members having ports and those of'the outer member being in spacedseries and initially closed bythe guide member, a tube for conducting gasolineunder pressure into the nozzle, a'

needle valve on the outer sleeve initially closing the tube, a rod support for the outer sleeve connected with the air valve, and rod supports for the inner sleeve carried by the body, means for heating the body to expand said. body, and adjustable spring means for regulating'the air unit valve 7 with respect to its seat.

OSEPH HEWITSONV 

